It was one small step for the Labour Party, but in terms of a morale boost it was one giant leap for party leader David Shearer. The lift for Labour in the two television network polls on Sunday was relatively small, taking it to about 35 per cent in both. The news was better for Shearer personally - he was noticeably up in terms of popularity in both polls, albeit still bobbing in Prime Minister John Key's wake.

Timing is everything - and Shearer needed that lift at exactly that time, not least because it appeared to sanction his own leadership while sounding a death knell for his rival, David Cunliffe, who languished well behind him in the poll.

Labour grabbed on the polls as the harbinger of a new season in the political cycle - the first little buds of a spring after the long, cruel winter that almost always sets in with gruesome ferocity after a party has enjoyed a lengthy summer in Government.

However, Shearer has now discovered every silver lining has a cloud. As the polls show a Labour and Green Party coalition becoming a force for National to reckon with, so the questions Shearer now faces have changed.

Rather than being asked simply what his own party would do in any given situation, Shearer now also has to work his way through the tangle of how Labour would deal with the Greens' apparently immutable position on any given issue.

The pullout from deep sea mining exploration by Petrobras was this week's test for Shearer - and mining, with its inherent conflict of jobs versus environment, is one area in which the tension between the two parties is most obvious.

Shearer also has to counter the scare campaign National is already running on the potential dangers of that coalition - and on that front, Shearer has at least put one peg in the ground, with a solid "no" when asked about Green co-leader Russel Norman's desire for the finance job in a future Government.

In between painting apocalyptic scenarios of that coalition, Key was engaged in a game of Cluedo - the spies version.

Sightings of a United States Government jet at Wellington Airport prompted inevitable questions about the passengers and why they were here.

Key took his role as game master very seriously. He gave out little dribbles of hints, one by one. He let slip it was something to do with intelligence agencies. Then he said it was no secret at all: the plane's very existence indicated there was no secrecy, because what fool would leave a distinctive jet sitting on the tarmac if they wanted to be sneaky?

Key's answers made up for what the plane lacked in secrecy. He claimed he did not know who was at the meeting, how they got there, or what the meetings were about. He had not seen Colonel Mustard, he did not know whether the library had been breached, he could not say whether it was tomato sauce or blood on the candlestick.

Just as in Cluedo, the answers were on a piece of paper somewhere but he couldn't really be bothered looking at it.

Intrigued by private jets arriving in the dead of night and pieces of paper the Prime Minister would not look at, the air of mystery built.

"Go to the United States Embassy," Key suggested, guru-like, to those seeking further enlightenment.

Those who did go to the US Embassy discovered nothing more than what their eyes had already told them: a US Government jet had been on the tarmac at Wellington Airport.

By now the game was more important than the answer. The more he refused to answer, the more he was asked. He knew full well that had he said who the visitor was from the beginning - or simply refused point-blank to answer at the start - it was highly likely the media would have yawned and hunted for another mystery.

However, the bonus in it for the Prime Minister was that it was a wonderful decoy. Every question about the jet, and the people it had disgorged onto an unwitting Wellington, was a question that wasn't about jobs, whether the surplus goal was now as wobbly as a trifle, whether New Zealand was 100 per cent pure, or that perennial - how his plans to stem the brain drain to Australia were shaping up.

He had nothing to lose by dodging such questions, beyond adding to the general impression that when it came to the whims of America, he was as pliable as a Len Lye wind wand.

Finally, after three days, the end of the game was in sight. Key had looked at the piece of paper and discovered there was a range of officials here, from a range of countries, for a range of "routine meetings".

Routine maybe, but it was "standard practice" to be secret squirrel about it all.